When John Mosler enthuses about clay bodies, glazes and kiln design, it is easy to forget he was once a shaper of global financial markets. But after a nearly 25-year career as a pioneer in the derivatives market, he made a clean break from finance to become a ceramist.

“In New York City, the draw of money and power is incredible,” Mr. Mosler, 55, said the other day...

If you’ve ever taken a ceramics class, you know that there’s ample opportunity for failure: Clay can dry too quickly and crumble; a piece may shrink in the kiln and emerge with cracks; the firing can go awry, causing glazes to turn murky colors.

Together he and his wife, designer,Jean Won Mosler, founder of Maum Design, put pretty much everything they had into transforming an industrial building in Gowanus, Brooklyn, so … now they have to make it work. “I’m an artist who needs to sell art … the place is purpose-built and it isn’t made to sell on to the next guy.”